Briquette and method of manufacture



No Drawing.

Patented Jan. 10, 1928.

UNITED STATES PATENT OFFICE.

LEMUEL M. JOHNSTON AND JAMES L. FARRELL, OF PARCO, WYOMING.

' BRIQUETTE AND METHOD OF MANUFACTURE.

Our invention relates to briquettes and a method of manufacture, and particularly to the utilization of certain by-products of the petroleum refining industry in making such briquettes.

In the refining of petroleum, it is common practice to. treat the lighter distillates and lubricating oils with sulphuric acid and such treatment causes a sludge to be precipitated, which sludge is generally called acid tars because of its tarlike characteristics and its acidity. These acid tars can be treated to recover the acid but at great expense, and the economical disposal of the acid tars in refineries is a serious problem.

Further, in coke stills and in pressure or cracking stills wherein crude petroleum or its derivatives are destructively distilled, coke is formed and must be removed from the stills and disposed of at suitable intervals. This coke is ofsubstantially pure car- 'bon and finds various limited uses, but the supply is so large that the economical disposal thereof is, like the acid tars, a matter of difliculty.

It is the principal purpose of our invention to utilize the acid tars of the character above referred to, and petroleum coke or other carbonaceous materials in the manufacture of briquettes, which will be an efficient fuel having many; advantages over other fuels now in use.

In the utilization of the by-products of I the petroleum industry above referred to,

we may first crush or pulverize the petroleum coke. Acid tars in proper proportions may then be added to the finely divided coke and the mixture well masticated and mixed. It is preferable to heat the acid tars so as to render the same quite fluid in order to obtain the proper mixture, and it is also desirable to heat the mass while mixing. The mixed coke and tars may then be formed into briquettes under suitable pressure. The

briquettes will of course contain the acid which was present in the tars, and this acid, if allowed to remain in the finished briquettes would have deleterious effects on the furnaces in which the briquettes are later burned. We therefore sub ect the formed briquettes to a roasting process which evaporates or drives 011' the acid, thus leavin the briquettes substantially free of acid, an therefore suitable for burning in ordinary furnaces.

While we. have mentioned petroleum coke Application filed February 24, 1926. Serial No. 90,409.

as desirable in forming the briquettes as above referred to, we wish it understood stantially pure carbon, and there is little mineral matterin'the acid tars to form ash.

The proportions of carbonaceous materials and acid tars will vary between quite wide limits dependent upon the character and fineness of the carbonaceous material, as well as upon the character and consistency of the acid tars. The tars as ordinarily formed, vary in consistency from a heavy asphalt to that of a light road oil, and obviously the amount of tars which can be successfully employed in mixing with car bonaceous materials will depend, as one factorupon the consistency and character of the tars. The proportions of the ingredients of the briquettes, however, should be such that an intimate mixture is obtained, and so that the carbonaceous material will be bound into a relatively uniform, or homogeneous mass, which will not be readily broken or powdered upon being handled, and the percentage of tars must .not be so highthat the form of the briquette will be su stantially altered upon being subjected to the roasting process. 'VVe may say, by wa of example, that with finely divided petro eum coke and an average sample of acid tars, approximately 15% of the tars and 85% of the carbonaceous material will give satisfactory results. Good results have also been obtained by mixing ground coke with about 6% of-acid sludge and, after briquetting, heating the briquettes to about 350 F. to drive off most of the acids; Higher temperatures produce a less smoky variety of fuel and a harder briquette usually results. Generally speaking the greatest practicable proportion of acid tars will give the greatest economic return since the tars are now of little use and therefore cheap, and the heat value of the tars is quite high.

The finished briquette of the character above referred to is a superior fuel in that there is substantially no ash residue upon being burned, may be made very dense and compact, will Withstand comparatively rough handling and shipment without substantial breakage or disintegration is easily ignited and burned, and may be burned so as to be substantially smoke free, is comparatively clean to handle, and the heat value is often as high as 15,500 B. t. u. per pound.

By so utilizing the two by-products of the petroleum industry above mentioned, we are able to form an excellent fuel, and also to provide a profitable means of disposal of the two byproducts and to thus turn what was formerly a substantial economic loss into a gain.

Another notable feature forming part of our invention is the recovery of certain byproducts from the acid tars and sometimes from the coke. The acid tars are of a very complex composition and contain many compounds among which may be mentioned ammonia, complex hydrocarbons, and alcohols, such as butyl and propyl alcohol. When the acidtars are heated sufficiently many of these compounds and others are vaporized, and since some of these are of considerable value should be recovered. 'We therefore propose to condense or otherwise collect certain or all of the products vaporized when the acid tars and coke are heated to drive off the acid.

In addition to recovering certain valuable I products from the acid tars we secure an added advantage, namely the forming of a usable residue and one which may be readily handled. It may not be necessary in all cases to mix the acid tars or sludge acid with carbonaceous material when the sole object in view is the recovery of the by-products of the acid tars such as those mentioned, and other material might be substituted for the comprises,

carbonaceous material so as to give a residue which is easily handled and disposed of. However, since carbonaceous material has been found to be satisfactory and the residue is a valuable product, namely a valuable fuel, We prefer to employ such carbonaceous ma terial with the acid tars or sludge acids.

lVhile we have described the invention in some detail, it is to be understood that the details may be changed without departing from the invention as defined in the ap pended claims.

e claim:

1. The method of utilizing acid tars which mixing the same with finely divided carbonaceous material, compressing the mixture into briquettes, and roasting to drive off the acid.

2. The method ofutilizing petroleum coke and acid tars resulting from the refining of petroleum which comprises, mixing the finely divided coke with the acid tars, compressing the mixture into briquettes, and roasting the briquettes to drive off the acid.

3. The method which comprises, pulverizing carbonaceous material. mixing the same with acid tars while heated, forming the mixture into briquettes, and then roasting to drive ofi the acid.

a. A briquette formed of finely divided carbonaceous material and a binder of acid tars, said briquette being readily ignit-able, of high fuel value, leaving substantially no ash residue, and relatively compact and tough to withstand rough handling.

5. The method which comprises, mixing acid tars with carbonaceous material, then heating the mixture to drive ofi' volatile products and collecting those products.

LEMUEL M. JOHNSTON. JAMES L FARRELL. 

